快速入门：Actors

开始使用 Dapr 的 Actors 构建块

让我们来看看Dapr的Actors构建块。在这个快速入门中，您将运行一个智能设备微服务和一个简单的控制台客户端，以演示 Dapr Actors 中的有状态对象模式。

当前，您可以使用.NET SDK来体验 actor 的快速入门。

.NET

作为 .NET actors 快速入门的一个简要概述：

使用一个 SmartDevice.Service 微服务，您可以托管:
- 两个 SmartDectectorActor 烟雾报警对象
- 一个 ControllerActor 对象，用于命令和控制智能设备
使用一个 SmartDevice.Client 控制台应用程序，客户端应用程序与每个actor或控制器进行交互，以执行聚合操作。
这 SmartDevice.Interfaces 包含服务和客户端应用使用的共享接口和数据类型。

先决条件

对于此示例，您将需要：

第1步：设置环境

克隆在Quickstarts存储库中提供的示例。

git clone https://github.com/dapr/quickstarts.git

第2步：运行服务应用

在一个新的终端窗口中，导航到 actors/csharp/sdk/service 目录并恢复依赖项：

cd actors/csharp/sdk/service
dotnet build

运行SmartDevice.Service，它将启动服务本身和Dapr sidecar：

dapr run --app-id actorservice --app-port 5001 --dapr-http-port 3500 --resources-path ../../../resources -- dotnet run --urls=http://localhost:5001/

预期输出：

== APP == info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
== APP ==       Request starting HTTP/1.1 GET http://127.0.0.1:5001/healthz - -
== APP == info: Microsoft.AspNetCore.Routing.EndpointMiddleware[0]
== APP ==       Executing endpoint 'Dapr Actors Health Check'
== APP == info: Microsoft.AspNetCore.Routing.EndpointMiddleware[1]
== APP ==       Executed endpoint 'Dapr Actors Health Check'
== APP == info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
== APP ==       Request finished HTTP/1.1 GET http://127.0.0.1:5001/healthz - - - 200 - text/plain 5.2599ms

步骤 3：运行客户端应用程序

在新的终端窗口中，导航到 actors/csharp/sdk/client 目录并安装依赖项：

cd ./actors/csharp/sdk/client
dotnet build

运行 SmartDevice.Client 应用程序：

dapr run --app-id actorclient -- dotnet run

预期输出：

== APP == Startup up...
== APP == Calling SetDataAsync on SmokeDetectorActor:1...
== APP == Got response: Success
== APP == Calling GetDataAsync on SmokeDetectorActor:1...
== APP == Device 1 state: Location: First Floor, Status: Ready
== APP == Calling SetDataAsync on SmokeDetectorActor:2...
== APP == Got response: Success
== APP == Calling GetDataAsync on SmokeDetectorActor:2...
== APP == Device 2 state: Location: Second Floor, Status: Ready
== APP == Registering the IDs of both Devices...
== APP == Registered devices: 1, 2
== APP == Detecting smoke on Device 1...
== APP == Device 1 state: Location: First Floor, Status: Alarm
== APP == Device 2 state: Location: Second Floor, Status: Alarm
== APP == Sleeping for 16 seconds before checking status again to see reminders fire and clear alarms
== APP == Device 1 state: Location: First Floor, Status: Ready
== APP == Device 2 state: Location: Second Floor, Status: Ready

（可选）第4步：在Zipkin中查看

如果您在计算机上本地为 Dapr 配置了 Zipkin，您可以在 Zipkin Web UI 中查看 actor 与客户端的交互（通常在 http://localhost:9411/zipkin/）。

发生了什么？

当您运行客户端应用程序时，会发生几件事情：

两个 SmartDetectorActor actors 在客户端应用程序中被创建，并且使用对象状态进行初始化：

ActorProxy.Create<ISmartDevice>(actorId, actorType)
proxySmartDevice.SetDataAsync(data)

这些对象是可重入的并且保存状态，正如 proxySmartDevice.GetDataAsync()所示。

// Actor Ids and types
var deviceId1 = "1";
var deviceId2 = "2";
var smokeDetectorActorType = "SmokeDetectorActor";
var controllerActorType = "ControllerActor";
Console.WriteLine("Startup up...");
// An ActorId uniquely identifies the first actor instance for the first device
var deviceActorId1 = new ActorId(deviceId1);
// Create a new instance of the data class that will be stored in the first actor
var deviceData1 = new SmartDeviceData(){
    Location = "First Floor",
    Status = "Ready",
};
// Create the local proxy by using the same interface that the service implements.
var proxySmartDevice1 = ActorProxy.Create<ISmartDevice>(deviceActorId1, smokeDetectorActorType);
// Now you can use the actor interface to call the actor's methods.
Console.WriteLine($"Calling SetDataAsync on {smokeDetectorActorType}:{deviceActorId1}...");
var setDataResponse1 = await proxySmartDevice1.SetDataAsync(deviceData1);
Console.WriteLine($"Got response: {setDataResponse1}");
Console.WriteLine($"Calling GetDataAsync on {smokeDetectorActorType}:{deviceActorId1}...");
var storedDeviceData1 = await proxySmartDevice1.GetDataAsync();
Console.WriteLine($"Device 1 state: {storedDeviceData1}");
// Create a second actor for second device
var deviceActorId2 = new ActorId(deviceId2);
// Create a new instance of the data class that will be stored in the first actor
var deviceData2 = new SmartDeviceData(){
    Location = "Second Floor",
    Status = "Ready",
};
// Create the local proxy by using the same interface that the service implements.
var proxySmartDevice2 = ActorProxy.Create<ISmartDevice>(deviceActorId2, smokeDetectorActorType);
// Now you can use the actor interface to call the second actor's methods.
Console.WriteLine($"Calling SetDataAsync on {smokeDetectorActorType}:{deviceActorId2}...");
var setDataResponse2 = await proxySmartDevice2.SetDataAsync(deviceData2);
Console.WriteLine($"Got response: {setDataResponse2}");
Console.WriteLine($"Calling GetDataAsync on {smokeDetectorActorType}:{deviceActorId2}...");
var storedDeviceData2 = await proxySmartDevice2.GetDataAsync();
Console.WriteLine($"Device 2 state: {storedDeviceData2}");

调用SmartDetectorActor 1的DetectSmokeAsync方法。

 public async Task DetectSmokeAsync()
 {
     var controllerActorId = new ActorId("controller");
     var controllerActorType = "ControllerActor";
     var controllerProxy = ProxyFactory.CreateActorProxy<IController>(controllerActorId, controllerActorType);
     await controllerProxy.TriggerAlarmForAllDetectors();
 }

调用ControllerActor的TriggerAlarmForAllDetectors方法。当检测到烟雾时，ControllerActor会内部触发所有警报

public async Task TriggerAlarmForAllDetectors()
{
    var deviceIds =  await ListRegisteredDeviceIdsAsync();
    foreach (var deviceId in deviceIds)
    {
        var actorId = new ActorId(deviceId);
        var proxySmartDevice = ProxyFactory.CreateActorProxy<ISmartDevice>(actorId, "SmokeDetectorActor");
        await proxySmartDevice.SoundAlarm();
    }
    // Register a reminder to refresh and clear alarm state every 15 seconds
    await this.RegisterReminderAsync("AlarmRefreshReminder", null, TimeSpan.FromSeconds(15), TimeSpan.FromSeconds(15));
}

控制台打印一条消息，指示检测到烟雾。

// Smoke is detected on device 1 that triggers an alarm on all devices.
Console.WriteLine($"Detecting smoke on Device 1...");
proxySmartDevice1 = ActorProxy.Create<ISmartDevice>(deviceActorId1, smokeDetectorActorType);
await proxySmartDevice1.DetectSmokeAsync();

调用 SmartDetectorActor 1 和 2 的 SoundAlarm 方法。

storedDeviceData1 = await proxySmartDevice1.GetDataAsync();
Console.WriteLine($"Device 1 state: {storedDeviceData1}");
storedDeviceData2 = await proxySmartDevice2.GetDataAsync();
Console.WriteLine($"Device 2 state: {storedDeviceData2}");

ControllerActor还会使用RegisterReminderAsync创建一个持久的提醒，在15秒后调用ClearAlarm。

// Register a reminder to refresh and clear alarm state every 15 seconds
await this.RegisterReminderAsync("AlarmRefreshReminder", null, TimeSpan.FromSeconds(15), TimeSpan.FromSeconds(15));

对于示例的完整上下文，请查看以下代码:

SmartDetectorActor.cs: 实现了智能设备 actor
ControllerActor.cs: 实现了管理所有设备的控制器 actor
ISmartDevice: 每个SmartDetectorActor的方法定义和共享数据类型
IController: ControllerActor的方法定义和共享数据类型

告诉我们您的想法

我们一直在努力改进我们的快速入门示例，并重视您的反馈。您觉得此快速入门有帮助吗？您有改进的建议吗？

加入我们的discord频道参与讨论。

下一步

了解更多关于Actor构建块

探索 Dapr 教程 >>